This invention relates to an improved method of manufacturing a composite panel using lauan and the panel made using the method (while the method is applicable to panels using lauan or other moisture-carrying or moisture-absorbing materials, reference will for the most part be limited to lauan, in the interest of conciseness). In the conventional production of composite panels with lauan, a gel coat layer is first laid down on a mold, followed by a layer of resin and glass fibers, thus forming a wet laminate. A layer of lauan is then applied directly to the wet laminate. The resin contains one or more promoters, and depending on the resin used, peroxide may also be added to the resin just before it is introduced into the mold. The peroxide acts as a cure initiator by reacting with the promoter and causing the resin to polymerize and harden. It additionally results in the resin bonding to the lauan, forming a flat, hard composite sheet.
Sometimes the lauan, although apparently exhibiting acceptable adhesion, does not form a strong bond to the cured laminate, resulting in a panel that can undergo delamination. The present inventor has determined that this problem is more likely to occur with increased water content of the lauan. The inventor thus believes that the problem is due to excess moisture in the lauan, and that this water inhibits the cure of the resin at the interface by interfering with the reaction between peroxide and promoter, resulting in poor adhesion to the lauan. Unfortunately, attempting to solve this problem by simply adding extra promoter to the resin is not practical. The extra promoter changes the speed at which polymerization occurs, thus causing timing problems in the production process, as well as increasing consumption of the promoter.
One might attempt to manage this problem by inspecting all lauan for moisture content before using it. This reduces the likelihood of producing panels that are subject to delamination, but requires extra labor for the inspection, as well as storing the high-moisture lauan and returning it to the vendor. Similarly, attempting to dry the too-moist pieces of lauan before use would require still more labor, as well as requiring the availability of drying equipment and use of energy for the drying process.